衰老晚期大鼠脑组织丙二醛及非水溶性蛋白的变化

选用ＳＤ大白鼠青年组（３个月）、衰老晚期组（３４－３６个月）各１０只，测定各组大海马、前额皮质、小脑皮质丙二醛（ＭＤＡ）和蛋白质含量的变化。结果如下：与青年组比较，衰老晚期鼠海马、前额皮质、小脑皮质ＭＤＡ和非水溶性蛋白、组织总蛋白含量均明显增多，海马的非小溶性蛋白在２年年龄组均高于其余２个脑区。衰老晚期前额皮质非小溶性蛋白含量明显高于小脑皮质本语文对ＭＤＡ和非小溶性蛋白在衰老晚期的改变的意义进行了     

大白鼠脑与松果体β肾上腺素能受体的老年性变化

目的 研究老年大鼠大脑皮质、海马、小脑皮质和松果体β-肾上腺素能受体的变化.方法 选用老年(20个月)和青年(3个月)SD大白鼠,以放射配基受体结合分析法测定大鼠大脑皮质、海马、小脑皮质和松果体β受体密度、比较2个年龄组上述脑区β受体含量变化及松果体β受体日夜周期变化.结果 与青年组比较,老年组大脑皮质、海马β受体含量明显降低(P<0.01),小脑皮质β受体含量变化不明显(P>0.05),松果体β受体含量在青年组白天明显高于夜间,而老年组变化不明显.结论 衰老时大鼠大脑皮质和海马β受体含量减少,松果体β受体含量的日夜周期改变消失.     

大白鼠与松果体β肾上腺素能受体的老年性变化

目的 研究老年大鼠大脑皮质、海马、小脑皮质和松果体β肾上腺素能受体的变化。方法 选用老年（２０个月）和青年（３个月）ＳＤ大白鼠,以放射配基受体结合分析法测定大鼠大脑皮质、海马、小脑皮和松果体β受体密度、比较２个年龄组上述脑区β受体含量变化及松果体β受体日周期变化。结果 与青年组比较,老年组大脑皮质、海马β受体含量明显降低（Ｐ〈０．０１）,小脑皮质β受体含量变化不明显（Ｐ〉０．０５）,松果体β受体含     

电磁辐射暴露后不同脑区的氧化应激反应

目的观察2 450 MHz的电磁辐射暴露后大鼠不同脑区的氧化应激反应。方法随机将大鼠分为对照组,1 mW/cm2组,5 mW/cm2组和10 mW/cm2组,分别接受功率密度为0 mW/cm2、1 mW/cm2、5 mW/cm2和10 mW/cm2的2 450 MHz的电磁辐射暴露,检测额皮质、海马、纹状体和小脑组织中的脂质过氧化产物(MDA)含量和过氧化氢酶(CAT)活性。结果额皮质MDA含量在1 mW/cm2组、5 mW/cm2组和10 mW/cm2组均可见增高。海马组织MDA含量升高见于5 mW/cm2组和10 mW/cm2组。额皮质和海马组织CAT活性在5 mW/cm2组和10 mW/cm2组均可见降低。纹状体和小脑MDA含量升高及CAT活性降低仅见于10 mW/cm2电磁辐射暴露组。结论 2 450 MHz的电磁辐射暴露引起了大鼠额皮质、海马、纹状体和小脑组织的氧化应激反应。电磁辐射暴露后,皮质和海马组织氧化应激反应较纹状体和小脑更为敏感。     

白藜芦醇对D-半乳糖诱导的亚急性衰老小鼠海马神经元的保护作用

目的 探讨白藜芦醇对亚急性衰老小鼠海马神经细胞的保护作用.方法 D-半乳糖颈背部皮下注射制备亚急性衰老小鼠模型,设正常对照组、对照组、高低剂量处理组和阳性对照组.第3周始,处理组分别给予白藜芦醇15、45mg/kg(低、高剂量)灌胃,对照组给予生理盐水或DMSO溶液灌胃.8周后,检测小鼠血清、脑组织中超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量.制作石蜡切片,尼氏染色观察小鼠海马CA1区形态结构,免疫组化检测P53蛋白表达,TUNEL法检测细胞凋亡.结果 各组小鼠海马组织形态结构无明显变化;与对照组相比,白藜芦醇45 mg/kg体重组小鼠血清和脑组织中SOD活性明显升高,MDA含量明显下降;白藜芦醇45 mg/kg体重组小鼠海马CA1区P53蛋白表达阳性细胞较对照组小鼠减少,但各组均无明显的凋亡细胞.结论 白藜芦醇能增强亚急性衰老小鼠的抗氧化功能,降低亚急性衰老小鼠海马CA1区神经元P53蛋白的表达.     

弓形虫PRU株慢性感染小鼠脑部包囊的时空分布特征

目的观察实验小鼠脑内包囊的时空分布特点,为探讨弓形虫感染引起的情志和行为改变提供病理基础。方法弓形虫PRU株经口感染小鼠,经HE染色和免疫组化检测,在显微镜下计算前额、海马、丘脑、小脑和杏仁核部位的包囊个数,然后随机选取上述部位的5个视野拍照,计算包囊的平均密度,并用方差分析比较不同脑组织包囊密度有无统计学差异。结果弓形虫感染30和90d时,HE染色和免疫组化后显微镜观察发现,小鼠不同位置弓形虫包囊密度差异有统计学意义,其中,丘脑的包囊密度最大,其次是前额皮质、海马、杏仁核,小脑的包囊密度最小。丘脑的包囊密度显著高于其他4个脑区（P〈0.01）,小脑的包囊密度显著低于其它4个部位（P〈0.01）,而前额皮质、海马和杏仁核所含的包囊密度差异无统计学意义（P〉0.05）;弓形虫感染1个月时,杏仁核包囊密度明显低于感染3个月（F=18.314,P〈0.001）,但是小脑的包囊密度高于感染3个月（F=18.314,P〈0.001）。结论弓形虫包囊在慢性感染小鼠不同脑组织内的分布具有时空特异性,这可能是其临床表现的病理学基础。     

天麻素对快速衰老小鼠大脑组织衰老相关基因表达的影响

目的研究天麻素对快速衰老小鼠(SAM)海马及其大脑额叶皮质中衰老相关基因表达的影响。方法采用RT-PCR方法对给予天麻素的SAM-P/8小鼠海马及额叶皮质中衰老相关基因的mRNA表达变化进行分析。结果所检测的衰老相关基因在SAM-P/8小鼠的海马和额叶皮质中均有表达。成年鼠应用天麻素组与成年组比较,在海马组织中SCN2BmRNA表达增加,Sortilin-1mRNA表达减少,MAP1BmRNA和RAP2AmRNA在额叶皮质中表达增加。老年鼠天麻素组MAPKK4、Sortilin-1和Rab6A在海马和额叶皮质中表达均比老年组减少。结论天麻素在分子水平上可能是通过调节部分衰老相关基因的表达水平来发挥其抗衰老作用,但对于衰老晚期,基因调控抗衰老的作用不明显。     

衰老晚期海马CA1区胶质细胞超微结构改变

选用SD大白鼠20只分青年组(3个月)、老年组(34～36个月),应用透视电镜观察比较海马CA1区胶质细胞的超微结构变化,结果如下:和青年组相比,老年组海马CAl区胶质细胞胞体及突起出现反应性增生、肥大,包绕神经元及终末,胶质细胞内的线粒体数量减少,肿胀、空洞化线粒体增多,粗面内质网稀疏,脂竭素沉积严重等改变,表现为胶质细胞严重退变,表明衰老晚期海马CA1区胶质细胞出现对神经元退变代偿的反应性增生,肥大的同时自身出现严重退变.     

慢性吗啡处理及戒断后大鼠前额皮质、海马和杏仁核中Parvalbumin的表达变化

为了观察慢性吗啡处理及戒断后大鼠前额皮质、海马和杏仁核中parvalbumin(PV)的表达变化,为其功能的研究提供形态学依据,本实验将30只雄性SD大鼠随机分为吗啡依赖组和生理盐水对照组。吗啡依赖组大鼠腹膜腔注射吗啡,2次/d,起始剂量为5mg/kg,逐日递增5mg,至第10d为50mg/kg;对照组注射同体积的生理盐水。于末次注射后动物分别存活3h、3d和14d。用免疫组化方法和相对平均灰度值检测前额皮质、海马和杏仁核内PV的表达。结果显示:在生理盐水处理组各存活时间点,前额皮质、海马和杏仁核内PV的表达相同。和生理盐水对照组相比,3h时海马和杏仁核内PV的表达明显增加(P<0.05),但前额皮质内PV的表达减少。第3d时,海马CA1、CA3、CA4、齿状回和杏仁核内PV的表达减少,但CA2区PV表达继续增加,而前额皮质的表达开始恢复。至第14d时,CA2区PV的表达开始恢复,但CA1、CA4和杏仁核内PV的表达又开始增加,明显高于第3d组(P<0.05)。以上结果提示慢性吗啡处理及戒断后PV的表达具有区域特异性和时相特异性;这种变化在戒断早期可能主要与躯体依赖相关,而戒断晚期主要与精神依赖相关。     

衰老晚期海马CA1区锥体细胞线粒体改变──电镜定量分析

选用成年健康SD大鼠20只.分为青年组（3个月）和老年组（34～36个月）二个实验组，每组10只。应用透射电镜结合体视学方法观察并比较了海马CA1区锥体细胞线粒体的变化，结果如下：和青年组相比，老年组肿胀、变性线粒体增多，体视学分析显示老年组线粒体密度和平均体积增大，线粒体数密度和比表面减少，线粒体切面积大小频数分布图向右侧迁移，显示到衰老晚期较小的线粒体数减少.较大的线粒体数增多。本研究结果表明，衰老晚期海马CA1区锥体细胞线粒体严重退变，进入失代偿状态。     

大鼠小脑皮质内突触素P38免疫反应产物的分布及年龄变化

用免疫组织化学方法结合图像分析研究突触素Ｐ３８免疫反应产物在Ｗｉｓｔａｒ大鼠小脑皮质的分布及年龄变化，结果显示：小脑皮质内的突触素Ｐ３８免疫反应产物呈板层分布，各层之间的 产物密度差异很大；在三个年龄组，小脑Ｖ，Ⅶ叶分子层突触素Ｐ３８免疫反应产物校正光密度值以青年组最大，成年组次之，老年组最小，各组间差异显著。     

Age-related changes of glial fibrillary acidic protein immunoreactive astrocytes in the rat cerebellar cortex.

Age-related changes of glial fibrillary acidic protein (GFAP) immunoreactivity were investigated in the cerebellar cortex of young (3 months), adult (12 months) and old (24 months) rats using immunohistochemical techniques associated with image analysis. In young rats, cell bodies of GFAP-immunoreactive astrocytes were found in the white matter and in the granular layer of cerebellar cortex. Radially-oriented branches of astrocytes which are sited in the granular layer were also observed in the molecular layer. The number of GFAP-immunoreactivity astrocytes of white matter was decreased in adult and old rats in comparison with young cohorts, whereas their size increased progressively from 3 to 24 months old. The number and the size of GFAP-immunoreactive astrocytes of the granular layer was similar in young and adult rats. An increased number and size of GFAP-immunoreactive astrocytes was noticeable in old rats in comparison with younger cohorts. The number of radially oriented branches of the molecular layer was the same in the three age groups investigated. The above results indicate that GFAP-immunoreactive astrocytes of rat cerebellar cortex undergo age-related changes. The not homogeneous sensitivity to aging of cerebellar astrocytes suggests that evaluation of changes of different cell populations of cerebellar cortex should represent an important step of research on aging cerebellum.     

Effects of early weaning on anxiety and prefrontal cortical and hippocampal myelination in male and female Wistar rats

We investigated developmental changes in myelin formation in the prefrontal cortex and the hippocampus, and behavioral effects of early weaning in Wistar rats. Early-weaned rats showed decreased numbers of open-arm entries in an elevated plus-maze in both sexes at 4 weeks old; this effect persisted in males, but ceased in females after this age. Expression of myelin basic protein (MBP) showed both age-dependent increases and sex differences; 4-week-old males exhibited higher MBP levels in the hippocampus, whereas 7-week-old males showed lower MBP levels in the prefrontal cortex compared to females of the same age. There was a tendency for group differences from weaning for the 21.5-kDa isoform in the prefrontal cortex. Although these results suggest that male rats are more vulnerable than females to early-weaning effects on anxiety-related behaviors, further detailed analysis is needed to clarify the functional relationship between myelination and anxiety-related behaviors.     

Age-related structural changes in the rat cerebellar cortex: effect of choline alfoscerate treatment.

The influence of ageing and of 3 months choline alfoscerate treatment on age-related microstructural changes in cerebellar cortex was studied in 3-, 12- and 24-month-old male Sprague-Dawley rats. The number of Purkinje and granule neurons, the density of Nissl bodies in the cytoplasm of Purkinje and granule neurons and the density of silver-gold impregnated fibres within molecular and granule cells layers were assessed by neurohistological and neurohistochemical techniques associated with microdensitometry and quantitative image analysis. The number of Purkinje and granule neurons was approximately the same in rats of 3 and 12 months and significantly decreased in 24-month-old animals. The density of Nissl bodies and of fine processes of silver-gold impregnated fibres were greatest in the cerebellar cortex of rats of 12 months of age, followed in descending order by 3- and 24-month-old rats. Both the density of Nissl bodies and of silver-gold impregnated fibres were significantly lower in the cerebellar cortex of the oldest age group considered in comparison with the young and middle age groups. Treatment with choline alfoscerate, a precursor in the biosynthesis of brain phospholipids which increases bioavailability of choline in the nervous tissue, noticeably reduced the loss of Purkinje and granule neurons in rats of 24 months. Moreover, it restored the density of Nissl bodies in the cytoplasm of Purkinje and granule neurons as well as the density of silver-gold stained fibres in the molecular and in the granule cells layers to values not significantly different from those found in rats of 3 months. These findings suggest that choline alfoscerate treatment may be effective in counteracting the age-dependent disarrangement of rat cerebellar cortex. The possible mechanisms of action of the compound on the microstructural changes of cerebellar cortex occurring with age are discussed.     

大鼠海马微血管构筑的定量分析及衰老变化

目的:观察并定量分析大鼠海马的微血管构筑及衰老变化。方法:采用单宁酸-氯化铁媒染微血管的方法分别观察青龄、老龄大鼠海马与额叶皮质的微血管构筑,并采用MiVnt图像分析系统对海马与额叶皮质的微血管密度(MVD)及微血管面积密度(MVA)进行定量分析。结果:老龄大鼠海马、皮质的微血管数量显著减少,分布杂乱、扭曲缠结。定量分析显示老龄大鼠海马、皮质的MVD值和MVA值均明显低于青龄大鼠,差异具有统计学意义。结论:老龄大鼠海马及额叶皮质的MVD值、MVA值均明显低于青龄大鼠,这是老年血管性痴呆发生机制的主要形态学依据。     

慢性不完全性睡眠剥夺对幼鼠学习记忆的影响

目的：探讨慢性不完全性睡眠剥夺对幼鼠学习记忆能力的影响及其可能机制。方法：建立慢性不完全性睡眠剥夺动物模型，并测定其空间学习记忆能力，同时对幼鼠大脑前额皮质及海马神经元性一氧化氮合酶(nNOS)的表达进行分析。结果：睡眠剥夺组幼鼠完成预定任务所需的时间及发生错误的次数均超过正常对照组。睡眠剥夺组的nNOS在前额皮质区域阳性、强阳性表达面积及在海马区域强阳性表达面积均大于正常对照组。结论：慢性不完全性睡眠剥夺会影响幼鼠的学习记忆能力，而前额皮质及海马中nNOS表达水平的下降可能是慢性不完全性睡眠剥夺影响未成熟脑学习记忆能力的机制之一。     

Muscarinic receptor-mediated GTP-Eu binding in the hippocampus and prefrontal cortex is correlated with spatial memory impairment in aged rats

The present study examined muscarinic receptor/G-protein coupling in the hippocampus and the prefrontal cortex of young and aged Long-Evans rats characterized for spatial learning ability in the Morris water maze. In a highly sensitive time-resolved fluorometry GTP-Eu binding assay, muscarinic-mediated GTP-Eu binding was severely blunted in hippocampus (-32%) and prefrontal cortex (-34%) as a consequence of aging. Furthermore, the magnitude of decreased muscarinic-mediated GTP-Eu binding was significantly correlated with the severity of spatial learning impairment in hippocampus and prefrontal cortex of aged rats and was specifically decreased in the subset of aged rats that were spatial learning impaired when compared to the aged unimpaired and the young rats. Western blot data indicated a preservation of the membrane-bound M1 receptor and the Galphaq/11 protein in both brain regions. These data demonstrate that muscarinic signaling is severely impaired as a consequence of normal aging in a manner that is closely associated with age-related cognitive decline.